The dataset delineates ecological sections within California deserts. These deserts occupy the southeastern portion of California and include two ecoregional provinces comprised of five desert regions ("ecological sections"; Miles and Goudey 1997). The American Semi-Desert and Desert Province (warm deserts) includes the Mojave Desert, Sonoran Desert, and Colorado Desert sections in the southern 83% of the California desert. The Intermountain Semi-Desert Province (cold deserts) includes the Southeastern Great Basin and Mono sections in the northern 17% of the region.